Water boards are similar to water skis. The water boarder is towed behind a powerful boat. The main difference, however, is that the water boarder kneels on his/her board. A strap is provided on the water board for the "boarder" to place over his/her thighs to keep the board in contact with the knees and shins of the boarder. It has been recognized that the stability of the water board can be greatly improved, under certain conditions, by the addition of two fins on the underside of the board. The fins provide control and lateral stability at high speeds. While this increase in stability is desirable for certain types of water boarding, there are other styles of water boarding wherein the fins are neither necessary nor desirable. One example of such a style would be jumping where the board and the boarder are towed across an inclined plane to gain altitude. Others would be spin-360s and side slides. The present invention provides a retractable feature for the fins.
The use of fins or skegs to impart stability is a technique known in water skiing, surfing, and sailing wherein the fin is called a keel. There are several patents which are typical of the design of water ski fins. U.S. Pat. No. 3,087,173 shows an adjustable, retractable fin positioned at the aft end of the ski. The fin is contained within a raised housing which protrudes above the plane of the ski surface. The position of the fin is controlled by two leaf springs and an s-shaped track through which a slide pin travels. U.S. Pat. No. 3,066,327 discloses a retractable stabilizer for water skis which pivots about a pin passing through the stabilizer and its housing disposed at the aft-end of the ski and above the ski surface. Latch means are provided to maintain the stabilizer in the retracted position. U.S. Pat. No. 3,082,444 describes a water ski safety skeg which is protected from damage from underwater debris and inclined ramps by its ability to automatically retract.
While the water board fin is subject to the same design criteria concerning underwater debris and ramps, etc., the water board presents a problem not present in water ski skeg design. This difference relates to the quality and quantity of user contact with the board. A water skier's contact with the water ski comprises the placement of his/her foot in a rubber binding. The remainder of the water skier's body is not intended to contact the ski. Thus, the stabilizers used on water skis are permitted to protrude above the surface of the ski without interfering with the skier. Water boards on the other hand must carefully guard against this above surface protrusion since the water boarder's knees and shins are in contact with the board surface all the way to its rear terminus. The location of the skegs at the aft end of the water board or ski results from the dynamics of the stabilizing phenomenon. This location is not subject to large degree of variation due to the dynamics of the board in motion. This invention provides a retractable fin which protrudes only minimally above the water board surface.
Therefore, it is an object of this invention to provide a retractable fin for a water board which does not interfere with the boarder's knees or shins.
It is a further object of this invention to provide a retractable fin which can be selected to be in the retracted position or in the extended position.